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| author | David Gibson <david@gibson.dropbear.id.au> | 2006-11-14 02:03:38 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.osdl.org> | 2006-11-14 09:09:27 -0800 |
| commit | cb07c9a1864a8eac9f3123e428100d5b2a16e65a (patch) | |
| tree | fadc568154bbe3c1466081b718e9638438c82c46 /mm/mmap.c | |
| parent | 68589bc353037f233fe510ad9ff432338c95db66 (diff) | |
| download | lwn-cb07c9a1864a8eac9f3123e428100d5b2a16e65a.tar.gz lwn-cb07c9a1864a8eac9f3123e428100d5b2a16e65a.zip | |
[PATCH] hugetlb: check for brk() entering a hugepage region
Unlike mmap(), the codepath for brk() creates a vma without first checking
that it doesn't touch a region exclusively reserved for hugepages. On
powerpc, this can allow it to create a normal page vma in a hugepage
region, causing oopses and other badness.
Add a test to prevent this. With this patch, brk() will simply fail if it
attempts to move the break into a hugepage reserved region.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index bdace87d7c01..2526463c99a7 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1880,6 +1880,10 @@ unsigned long do_brk(unsigned long addr, unsigned long len) if ((addr + len) > TASK_SIZE || (addr + len) < addr) return -EINVAL; + error = is_hugepage_only_range(current->mm, addr, len); + if (error) + return error; + flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags; error = arch_mmap_check(addr, len, flags); |